Add files via upload
This commit is contained in:
Frank Adams
GitHub
parent
c01c69fc3a
commit
f1fe131aab
1 changed files with 581 additions and 0 deletions
581
Example_Touchpads/Touchpad_Stream_mode.ino
Normal file
581
Example_Touchpads/Touchpad_Stream_mode.ino
Normal file
|
|
@ -0,0 +1,581 @@
|
|||
//
|
||||
// This software interfaces a Teensy 3.2 with a PS/2 laptop touchpad.
|
||||
// The touchpad is commanded to be in Stream Mode (not remote mode).
|
||||
// This causes the touchpad to send data when ever it detects finger movement.
|
||||
// The ps/2 code uses the USB PJRC Mouse functions at www.pjrc.com/teensy/td_mouse.html
|
||||
// The ps/2 code has a watchdog timer so the code can't hang if a clock edge is missed.
|
||||
// In the Arduino IDE, select Tools, Teensy 3.2. Also under Tools, select Keyboard+Mouse+Joystick
|
||||
//
|
||||
// Revision History
|
||||
// Rev 1.0 - Aug 1, 2020 - Original Release
|
||||
//
|
||||
// The touchpad ps/2 data and clock lines are connected to the following Teensy I/O pins
|
||||
#define TP_DATA 0
|
||||
#define TP_CLK 1
|
||||
// Teensy LED will be turned ON to show if errors are detected during initialization or during normal use
|
||||
#define ERROR_LED 13
|
||||
//
|
||||
// Declare variables that will be used by functions
|
||||
boolean init_error = LOW; // set high if initialization detects an error
|
||||
boolean bit_error = LOW; // set high if main loop detects an error
|
||||
char mstat; // touchpad status 8 bit register = Y overflow, X overflow, Y sign bit, X sign bit, Always 1, Middle Btn, Right Btn, Left Btn
|
||||
char mx; // touchpad x movement = 8 data bits. The sign bit is in the status register to
|
||||
// make a 9 bit 2's complement value. Left to right on the touchpad gives a positive value.
|
||||
char my; // touchpad y movement also 8 bits plus sign bit in status reg. Touchpad movement away from the user gives a positive value.
|
||||
//
|
||||
// Function to set a pin to high impedance (acts like open drain output)
|
||||
void go_z(int pin)
|
||||
{
|
||||
pinMode(pin, INPUT);
|
||||
digitalWrite(pin, HIGH);
|
||||
}
|
||||
//
|
||||
// Function to set a pin as an input with a pullup
|
||||
void go_pu(int pin)
|
||||
{
|
||||
pinMode(pin, INPUT_PULLUP);
|
||||
digitalWrite(pin, HIGH);
|
||||
}
|
||||
//
|
||||
// Function to set a pin to a logic low
|
||||
void go_0(int pin)
|
||||
{
|
||||
pinMode(pin, OUTPUT);
|
||||
digitalWrite(pin, LOW);
|
||||
}
|
||||
//
|
||||
// Function to set a pin to a logic high
|
||||
void go_1(int pin)
|
||||
{
|
||||
pinMode(pin, OUTPUT);
|
||||
digitalWrite(pin, HIGH);
|
||||
}
|
||||
//
|
||||
// *****************Functions for Touchpad***************************
|
||||
//
|
||||
// Function to send the touchpad a byte of data (command)
|
||||
//
|
||||
void tp_write(char send_data)
|
||||
{
|
||||
unsigned int timeout = 200; // breakout of loop if watchdog over this value in msec
|
||||
elapsedMillis watchdog; // zero the watchdog timer clock
|
||||
char odd_parity = 0; // clear parity bit count
|
||||
// Enable the PS/2 bus by floating the clock and data
|
||||
go_pu(TP_CLK); //
|
||||
go_pu(TP_DATA); //
|
||||
delayMicroseconds(250); // wait before requesting the bus
|
||||
go_0(TP_CLK); // Send the Clock line low to request to transmit data
|
||||
delayMicroseconds(100); // wait for 100 microseconds per bus spec
|
||||
go_0(TP_DATA); // Send the Data line low (the start bit)
|
||||
delayMicroseconds(1); //
|
||||
go_pu(TP_CLK); // Release the Clock line so it is pulled high
|
||||
delayMicroseconds(1); // give some time to let the clock line go high
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
if (watchdog >= timeout) { //check for infinite loop because tp did not respond
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
// send the 8 bits of send_data
|
||||
for (int j=0; j<8; j++) {
|
||||
if (send_data & 1) { //check if lsb is set
|
||||
go_pu(TP_DATA); // send a 1 to TP
|
||||
odd_parity = odd_parity + 1; // keep running total of 1's sent
|
||||
}
|
||||
else {
|
||||
go_0(TP_DATA); // send a 0 to TP
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
send_data = send_data >> 1; // shift data right by 1 to prepare for next loop
|
||||
}
|
||||
// send the parity bit
|
||||
if (odd_parity & 1) { //check if lsb of parity is set
|
||||
go_0(TP_DATA); // already odd so send a 0 to TP
|
||||
}
|
||||
else {
|
||||
go_pu(TP_DATA); // send a 1 to TP to make parity odd
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
go_pu(TP_DATA); // Release the Data line so it goes high as the stop bit
|
||||
delayMicroseconds(80); // testing shows delay at least 40us
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
delayMicroseconds(1); // wait to let the data settle
|
||||
if (digitalRead(TP_DATA)) { // Ack bit s/b low if good transfer
|
||||
}
|
||||
while ((digitalRead(TP_CLK) == LOW) || (digitalRead(TP_DATA) == LOW)) { // loop if clock or data are low
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
// Inhibit the bus so the tp only talks when we're listening
|
||||
go_0(TP_CLK);
|
||||
}
|
||||
//
|
||||
// Function to get a byte of data from the touchpad
|
||||
//
|
||||
char tp_read(void)
|
||||
{
|
||||
unsigned int timeout = 200; // breakout of loop if over this value in msec
|
||||
elapsedMillis watchdog; // zero the watchdog timer clock
|
||||
char rcv_data = 0; // initialize to zero
|
||||
char mask = 1; // shift a 1 across the 8 bits to select where to load the data
|
||||
char rcv_parity = 0; // count the ones received
|
||||
go_pu(TP_CLK); // release the clock
|
||||
go_pu(TP_DATA); // release the data
|
||||
delayMicroseconds(5); // delay to let clock go high
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
if (digitalRead(TP_DATA)) { // Start bit s/b low from tp
|
||||
// start bit not correct - put error handler here if desired
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
for (int k=0; k<8; k++) {
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
if (digitalRead(TP_DATA)) { // check if data is high
|
||||
rcv_data = rcv_data | mask; // set the appropriate bit in the rcv data
|
||||
rcv_parity++; // increment the parity bit counter
|
||||
}
|
||||
mask = mask << 1;
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
}
|
||||
// receive parity
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
if (digitalRead(TP_DATA)) { // check if received parity is high
|
||||
rcv_parity++; // increment the parity bit counter
|
||||
}
|
||||
rcv_parity = rcv_parity & 1; // mask off all bits except the lsb
|
||||
if (rcv_parity == 0) { // check for bad (even) parity
|
||||
init_error = HIGH;
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
// stop bit
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
if (digitalRead(TP_DATA) == LOW) { // check if stop bit is bad (low)
|
||||
// send bad stop bit to future error handler
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
if (watchdog >= timeout) { //check for infinite loop
|
||||
init_error = HIGH;
|
||||
break; // break out of infinite loop
|
||||
}
|
||||
}
|
||||
// Inhibit the bus so the tp only talks when we're listening
|
||||
go_0(TP_CLK);
|
||||
return rcv_data; // pass the received data back
|
||||
}
|
||||
//
|
||||
// Function to decode 3 bytes of data from the touchpad = status, X Delta, Y Delta
|
||||
//
|
||||
void tp_packet(void)
|
||||
{
|
||||
// ******************************Receive Byte 0 = Status***********************
|
||||
char rcv_data = 0; // initialize to zero
|
||||
char mask = 1; // shift a 1 across the 8 bits to select where to load the data
|
||||
char rcv_parity = 0; // count the ones received
|
||||
go_pu(TP_CLK); // release the clock
|
||||
go_pu(TP_DATA); // release the data
|
||||
delayMicroseconds(5); // delay to let clock go high
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
}
|
||||
if (digitalRead(TP_DATA)) { // Start bit s/b low from tp
|
||||
// start bit not correct - put error handler here if desired
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
}
|
||||
for (int k=0; k<8; k++) {
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
}
|
||||
if (digitalRead(TP_DATA)) { // check if data is high
|
||||
rcv_data = rcv_data | mask; // set the appropriate bit in the rcv data
|
||||
rcv_parity++; // increment the parity bit counter
|
||||
}
|
||||
mask = mask << 1;
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
}
|
||||
}
|
||||
// receive parity
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
}
|
||||
if (digitalRead(TP_DATA)) { // check if received parity is high
|
||||
rcv_parity++; // increment the parity bit counter
|
||||
}
|
||||
rcv_parity = rcv_parity & 1; // mask off all bits except the lsb
|
||||
if (rcv_parity == 0) { // check for bad (even) parity
|
||||
bit_error = HIGH;
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
}
|
||||
// stop bit
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
}
|
||||
if (digitalRead(TP_DATA) == LOW) { // check if stop bit is bad (low)
|
||||
bit_error = HIGH;
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
}
|
||||
mstat = rcv_data; // save data result in status byte
|
||||
// ******************************Receive Byte 1 = Delta X**************************
|
||||
rcv_data = 0; // initialize to zero
|
||||
mask = 1; // shift a 1 across the 8 bits to select where to load the data
|
||||
rcv_parity = 0; // count the ones received
|
||||
delayMicroseconds(5); // delay to let the clock stop ringing
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
}
|
||||
if (digitalRead(TP_DATA)) { // Start bit s/b low from tp
|
||||
// start bit not correct - put error handler here if desired
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
}
|
||||
for (int k=0; k<8; k++) {
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
}
|
||||
if (digitalRead(TP_DATA)) { // check if data is high
|
||||
rcv_data = rcv_data | mask; // set the appropriate bit in the rcv data
|
||||
rcv_parity++; // increment the parity bit counter
|
||||
}
|
||||
mask = mask << 1;
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
}
|
||||
}
|
||||
// receive parity
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
}
|
||||
if (digitalRead(TP_DATA)) { // check if received parity is high
|
||||
rcv_parity++; // increment the parity bit counter
|
||||
}
|
||||
rcv_parity = rcv_parity & 1; // mask off all bits except the lsb
|
||||
if (rcv_parity == 0) { // check for bad (even) parity
|
||||
bit_error = HIGH;
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
}
|
||||
// stop bit
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
}
|
||||
if (digitalRead(TP_DATA) == LOW) { // check if stop bit is bad (low)
|
||||
bit_error = HIGH;
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
}
|
||||
mx = rcv_data; // save data result in delta x byte
|
||||
// Receive Byte 1 = Delta Y
|
||||
// ******************************Receive Byte 2 = Delta Y**************************
|
||||
rcv_data = 0; // initialize to zero
|
||||
mask = 1; // shift a 1 across the 8 bits to select where to load the data
|
||||
rcv_parity = 0; // count the ones received
|
||||
delayMicroseconds(5); // delay to let the clock stop ringing
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
}
|
||||
if (digitalRead(TP_DATA)) { // Start bit s/b low from tp
|
||||
// start bit not correct - put error handler here if desired
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
}
|
||||
for (int k=0; k<8; k++) {
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
}
|
||||
if (digitalRead(TP_DATA)) { // check if data is high
|
||||
rcv_data = rcv_data | mask; // set the appropriate bit in the rcv data
|
||||
rcv_parity++; // increment the parity bit counter
|
||||
}
|
||||
mask = mask << 1;
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
}
|
||||
}
|
||||
// receive parity
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
}
|
||||
if (digitalRead(TP_DATA)) { // check if received parity is high
|
||||
rcv_parity++; // increment the parity bit counter
|
||||
}
|
||||
rcv_parity = rcv_parity & 1; // mask off all bits except the lsb
|
||||
if (rcv_parity == 0) { // check for bad (even) parity
|
||||
bit_error = HIGH;
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
}
|
||||
// stop bit
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == HIGH) { // loop until the clock goes low
|
||||
}
|
||||
if (digitalRead(TP_DATA) == LOW) { // check if stop bit is bad (low)
|
||||
bit_error = HIGH;
|
||||
}
|
||||
delayMicroseconds(1); // delay to let the clock settle out
|
||||
while (digitalRead(TP_CLK) == LOW) { // loop until the clock goes high
|
||||
}
|
||||
my = rcv_data; // save data result in delta y byte
|
||||
//
|
||||
// Inhibit the bus so the tp only talks when we're listening
|
||||
go_0(TP_CLK);
|
||||
}
|
||||
//
|
||||
void touchpad_init()
|
||||
{
|
||||
init_error = LOW; // start with no error
|
||||
go_pu(TP_CLK); // float the clock and data to touchpad
|
||||
go_pu(TP_DATA);
|
||||
// Sending reset command to touchpad
|
||||
tp_write(0xff);
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
delay(1000); // wait 1 second so tp can run its self diagnostic
|
||||
// verify proper response from tp
|
||||
if (tp_read() != 0xaa) { // verify basic assurance test passed
|
||||
init_error = HIGH;
|
||||
}
|
||||
if (tp_read() != 0x00) { // verify basic assurance test passed
|
||||
init_error = HIGH;
|
||||
}
|
||||
// Send touchpad disable code so that the mode byte can be loaded next
|
||||
tp_write(0xf5); // tp disable
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
// Load Mode Byte with 00 using the following special sequence from page 38 of Synaptics Interfaceing Guide.
|
||||
// Send set resolution to 0 four times followed by a set sample rate to 0x14
|
||||
// The resolution and sample rate are not actually changed but instead it loads the mode byte.
|
||||
// #1 set resolution
|
||||
tp_write(0xe8); // set resolution (actually part of setting mode byte)
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
tp_write(0x00); // to zero
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
// #2 set resolution (actually part of setting mode byte)
|
||||
tp_write(0xe8); // set resolution
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
tp_write(0x00); // to zero
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
// #3 set resolution
|
||||
tp_write(0xe8); // set resolution
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
tp_write(0x00); // to zero
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
// #4 set resolution (actually part of setting mode byte)
|
||||
tp_write(0xe8); // set resolution
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
tp_write(0x00); // to zero
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
// Set sample rate (actually part of setting mode byte)
|
||||
tp_write(0xf3); // set sample rate
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
tp_write(0x14); // to 14 hex
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
// This completes the mode byte load
|
||||
// set the resolution for real
|
||||
tp_write(0xe8); // Sending resolution command
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
tp_write(0x03); // value of 0x03 = 8 counts/mm resolution (default is 4 counts/mm)
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
// set the sample rate for real
|
||||
tp_write(0xf3); // Sending sample rate command
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
tp_write(0x28); // 0x28 = 40 samples per second, the default value used for Synaptics TP
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
// Load stream mode command so tp will send data whenever it's available
|
||||
tp_write(0xea); // stream mode
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
// Send touchpad enable code
|
||||
tp_write(0xf4); // tp enable
|
||||
if (tp_read() != 0xfa) { // verify correct ack byte
|
||||
init_error = HIGH;
|
||||
}
|
||||
}
|
||||
//
|
||||
// ************************************Begin Routine*********************************************************
|
||||
void setup() {
|
||||
pinMode(ERROR_LED, OUTPUT); // define teensy I/O 13 as an output
|
||||
touchpad_init(); // reset tp and check that self diagnostic passed. Put tp in stream mode and enable it
|
||||
digitalWrite(ERROR_LED, init_error); //LED off means touchpad passed its power up test, ACKed all communications, and never caused a watchdog timeout
|
||||
delay(5000); // wait 5 seconds to show init_error LED status
|
||||
digitalWrite(ERROR_LED, LOW); // Turn off LED for 1/2 second
|
||||
delay(500); // 1/2 second delay
|
||||
digitalWrite(ERROR_LED, HIGH); // Turn on LED momentarily to indicate code is in main loop
|
||||
delay(500); // 1/2 second delay
|
||||
digitalWrite(ERROR_LED, bit_error); // Turn off LED and switch its function to show bit errors in main loop
|
||||
}
|
||||
//
|
||||
// declare and initialize variables
|
||||
boolean over_flow; // set if x or y movement values are bad due to overflow
|
||||
boolean left_button = 0; // on/off variable for left button = bit 0 of mstat
|
||||
boolean right_button = 0; // on/off variable for right button = bit 1 of mstat
|
||||
boolean old_left_button = 0; // on/off variable for left button status the previous polling cycle
|
||||
boolean old_right_button = 0; // on/off variable for right button status the previous polling cycle
|
||||
boolean button_change = 0; // Active high, shows when a touchpad left or right button has changed since last polling cycle
|
||||
//
|
||||
// ************************************Main Loop***************************************************************
|
||||
void loop() {
|
||||
// Touchpad is enabled and in stream mode
|
||||
tp_packet(); // this function loops until there is bus activity and then saves data into mstat, mx, and my bytes for USB transmission below.
|
||||
if (((0x80 & mstat) == 0x80) || ((0x40 & mstat) == 0x40)) { // x or y overflow bits set?
|
||||
over_flow = 1; // set the overflow flag
|
||||
}
|
||||
// change the x data from 9 bit to 8 bit 2's complement by throwing away lsb
|
||||
mx = mx & 0x7f; // mask off 8th bit
|
||||
if ((0x10 & mstat) == 0x10) { // move the sign into
|
||||
mx = 0x80 | mx; // the 8th bit position
|
||||
}
|
||||
// change the y data from 9 bit to 8 bit 2's complement by throwing away lsb
|
||||
my = my & 0x7f; // mask off 8th bit
|
||||
if ((0x20 & mstat) == 0x20) { // move the sign into
|
||||
my = 0x80 | my; // the 8th bit position
|
||||
}
|
||||
// Invert the 8 bit value because y movement in ps/2 format is the opposite direction in touchpad.move function
|
||||
my = (~my + 0x01); // invert the y data by taking the 2's complement (invert and add 1)
|
||||
// zero out mx and my if over_flow is detected because the data is garbage
|
||||
if (over_flow) {
|
||||
mx = 0x00;
|
||||
my = 0x00;
|
||||
bit_error = HIGH; // flag an error
|
||||
}
|
||||
// Send the x and y data back via usb if either one is non-zero
|
||||
if ((mx != 0x00) || (my != 0x00)) {
|
||||
Mouse.move(mx,my);
|
||||
}
|
||||
//
|
||||
// pull out the left and right button status bits from the mstat byte
|
||||
if ((0x01 & mstat) == 0x01) { // is bit 1 set
|
||||
left_button = 1; // set the left_button status
|
||||
}
|
||||
else { // clear the left_button status
|
||||
left_button = 0;
|
||||
}
|
||||
if ((0x02 & mstat) == 0x02) { // is bit 2 set
|
||||
right_button = 1; // set the right_button status
|
||||
}
|
||||
else { // clear the right_button status
|
||||
right_button = 0;
|
||||
}
|
||||
// Determine if the left or right touch pad buttons have changed
|
||||
button_change = (left_button ^ old_left_button) | (right_button ^ old_right_button);
|
||||
// Don't send button status if there's no change since last usb button transmission.
|
||||
if (button_change){
|
||||
Mouse.set_buttons(left_button, 0, right_button); // send button status
|
||||
old_left_button = left_button; // remember new button status for next polling cycle
|
||||
old_right_button = right_button;
|
||||
}
|
||||
//
|
||||
digitalWrite(ERROR_LED, bit_error); // LED is used to show NACK, bad parity, overflow, or bad stop bits. Any error is latched "on"
|
||||
}
|
||||
Loading…
Reference in a new issue